1. Field of the Disclosure
This disclosure relates generally to completion strings deployed in multi-zone production wellbores that include valves for separately flowing formation fluids from different zones.
2. Background
Wellbores are drilled in subsurface formations for the production of hydrocarbons (oil and gas). Modern wells can extend to great well depths, often more than 15,000 ft. Hydrocarbons are trapped in various traps or zones in the subsurface formations at different depths. Such zones are referred to as reservoirs or hydrocarbon-bearing formations or production zones. In a multi-zone well bore, it is often desired to flow the formation fluid separately from two or more zones. Valves, generally, referred to annular valves, have been used that include a central flow path and an annular flow path to provide concentric fluid flow paths from different zones. Such valves, typically, are conveyed in the wellbore with the annular path open. The annular flow path is closed downhole to perform pressure tests and then opened hydraulically by applying pressure in the central flow path.
The disclosure herein provides a production string that includes an annular valve, wherein an annular flow path may be closed and opened mechanically or opened hydraulically by supplying a fluid to the annular flow path.